1. Field of Invention
This invention relates to a novel method for remodeling of the femoral head and to prosthetic means, including an intramedullary insert and attached or integral shell or cap, for use as a part of the said femoral head remodeling procedure, and to a drilling fixture for use in carrying out the method.
The ultimate product of the present invention may be employed with an intact acetabulum, namely, the cup-shaped socket in the hip bone, or in combination with prosthetic acetabular sockets or cups, which are widely available from orthopaedic supply organizations today and which are well known in the art. A representative prosthetic acetabular socket is disclosed in U.S. Pat. No. 3,722,002. Representative orthopaedic supply houses specializing in prosthetic acetabular sockets include DePuy, Howmedica, and Zimmer.
As is well known in the art, the hip joint comprises the acetabula or an acetabular prosthesis, which is a cup-shaped socket in the hip bone, providing a generally hemispheric surface, within which the femoral head, having a corresponding generally hemispheric surface contour, rotates by means of a thin layer of cartilage under normal conditions and on a thin layer of plastic or the like under conditions of reconstruction and prosthesis after the normal cartilage has become eroded or the hip joint has become otherwise inoperative due to aging, injury, or other abnormal condition arising from any of a multitude of etiologies.
The ultimate product of the present invention, which is a femur having a remodeled femoral head including prosthetic means comprising the intramedullary insert and its integral or attached cap, is intended for use in cooperation with a normal or prosthetic acetabular socket, but the provision of such acetabular socket does not constitute a part of the present invention.
Reference is made to my previous U.S. Pat. No. 4,532,661, issued Aug. 6, 1985, entitled "Femoral Head Remodeling and Prosthetic Means Therefor" and to U.S. Pat. No. 4,670,015, issued Jun. 2, 1987 to Freeman and entitled "Hip Implant", the disclosures of which prior patents are referred to herein and by reference made a part hereof. In the opinion of the present inventor, the developments of these two (2) patents are at the cutting edge of technology in the hip implant and femoral insert technology and methodology.
2. Prior Art
The prior art is replete with procedure and prosthetic means for remodeling of the femoral head. This is well documented in my previous U.S. Pat. No. 4,532,661 of Aug. 6, 1985, to which reference is now made and the entire disclosure of which is incorporated herein by reference.
Another recently-issued U.S. Patent to which reference is made is the aforesaid Freeman U.S. Pat. No. 4,670,015 of Jun. 2, 1987, which provides a somewhat more simplified version of a prosthetic means, comprising an intramedullary insert with an integral cap, than disclosed in my previous U.S. Pat. No. 4,532,661, upon either of which prior art devices, and methods which employ the same, the present invention is a highly-advantageous and valuable improvement, although relatively simple in its nature and approach, providing superior load-bearing characteristics and stability in use or operation.